Yes, they're very strict here; the drinking/smoking age is 19 and you must provide ID. No drinking on the street or anywhere in public, no children allowed in bars that serve food (but children are allowed in restaurants that serve alcohol!) and if I take my students out for a beer, only passports are acceptable and there are NO exceptions!

Nah, prolly less, cos less chance to get drunk at home, one can still drink anything at a bar or club, chance cannot buy alochol to take home.

I used to live in Sumatra. Alcohol is not easy to buy but it is not difficult. You just haven't found the right place yet. There are lots of non-muslim Chinese in Indonesia who drink. Maybe a trip to Chinatown is in order!